A235341 Positive integers a such that there exist b, c with 1/a + 1/b + 1/c = 1/3 and a >= b >= c.

9, 12, 15, 18, 20, 21, 24, 28, 30, 36, 42, 45, 48, 60, 84, 120, 156

Offset

1,1

Comments

See A236681 for motivation.

Links

Table of n, a(n) for n=1..17.

Example

The solutions are {[9, 9, 9], [12, 8, 8], [15, 10, 6], [18, 9, 6], [20, 12, 5], [21, 7, 7], [24, 8, 6], [28, 21, 4], [30, 10, 5], [36, 18, 4], [42, 7, 6], [45, 9, 5], [48, 16, 4], [60, 15, 4], [84, 14, 4], [120, 8, 5], [156, 13, 4]}.

Prog

(PARI) S=1/3; for(a=1+1\S, 999, for(b=ceil(2/(S-1/a)), a, numerator(S-1/a-1/b)==1 && print1(a", ")+next(2)))

Crossrefs

Sequence in context: A248903 A138945 A119486 * A356333 A342082 A365408

Adjacent sequences: A235338 A235339 A235340 * A235342 A235343 A235344

Keyword

nonn,fini,full

Author

M. F. Hasler, Jan 30 2014

Status

approved